


Hound

by hovercraft



Category: Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: Blow Jobs, M/M, Plot What Plot/Porn Without Plot, Rough Kissing, Rough Sex, Showers
Language: English
Status: Completed
Published: 2019-04-23
Updated: 2019-04-23
Packaged: 2020-01-24 13:08:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,583
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18572116
Author URL: https://archiveofourown.org/users/hovercraft/pseuds/hovercraft
Summary: Diarmuid finds himself earning the attention of someone unexpected. Cu Alter finds himself interested when his usual answer to everything is apathy.Part of a fic/art exchange.





	Hound

Cu Alter was nothing more than a distorted mirror of Medb’s perverse desires, and yet—

His three other selves would look at him with a worried disgust at what could have been, and yet—

Did Diarmuid pity the beast? Somewhat. He knew what it’s like to be betrayed so thoroughly it changes you, and to do the same to someone else. He could never imagine being changed by a wish into a twisted monster that no longer had a purpose. Dethroned, now summoned, Cu Alter lived to do nothing but fight with nothing to rule over. He was scornful of everyone he came across and held almost nothing in reverence. Gone was his honor, along with everything else that had made him Cu Chulainn.

What did that feel like? To know who you were supposed to be… and not be able to feel like yourself anymore?

Diarmuid spent more and more time with him, mainly because Cu liked picking fights and he had more fun if there was someone who could keep up. He basically volunteered to keep the beast from doing nothing but sleeping all day and ravaging Ritsuka’s foes. It was with a strange sense of assurance that Diarmuid quickly realized he was becoming Cu’s friend… even if Cu Alter would never call him one.

Cu Alter started sitting beside him at meetings or expected Diarmuid to take a seat beside him. He listened to him talk, and though he never had anything not rude to add, he never quite spat barbs the way he did with anyone else. If Cu Alter was unable to respect anything but power, Diarmuid wasn’t sure if he should be flattered or not. He had befriended him because he thought about how lonely his life was, and that he made sure Cu never picked up on, and since then, it… grew.

In Chaldea’s shower room, Diarmuid let the near boiling hot water dampen his hair and run rivulets down his skin. He was coming to terms with the fact that there’s something very attractive about the beast. Not that he’d ever admit it, especially not to Cu himself, who was apathetic to anything but fighting. There was something about his quiet watch and sharp teeth that gave Diarmuid a start whenever he grinned—he was amazed he had the vigor in him to grin at all. It did him no good to chase people who were uninterested, especially as a heroic spirit, especially under Ritsuka’s care—

Someone opened the door into the showers. Diarmuid sighed. Who else but the object of his thoughts?

He must have gotten done with something violent, as he reeked of blood and it stained his chest and clothes. Cu Alter let out a dissatisfied grunt as he pulled off his hood, the decorative piece around his shoulder with the ruff of fur. Diarmuid watched in fascination as the pieces of decoration and the pieces that were actual monster parts became distinguished—it turned out nothing but the tail was part of his body, but he sure had a hell of a hard time removing it all.

Diarmuid remembered to avert his gaze just in time for Cu to turn on the shower next to his and step beneath it. Red circled the drain as he washed out the aftermath of whatever he tore apart during a rayshift with Ritsuka.

“Hn.” Apparently ‘Diarmuid’ was four syllables too many to address him with, but at least Diarmuid was used to it by now.

“Rough time, eh?”

“The opposite. It was too easy.” Cu pulled his hair out of his ponytail and let it stick damp to his back.

Everything was too easy for Cu Alter. Already too strong for his own good, nothing posed a challenge anymore besides their sparring. Dodging a spear that would leave a wound that wouldn’t heal was more fun than a regular one.

Diarmuid’s gaze fixated on Cu’s body for longer than he would have liked in a side glance—he was muscular and proudly scarred, with the tattoos on his body providing the perfect offset to his skin. This was someone he could never have, so he turned his head away from him and decided this would be enough.

Or it would be, if he hadn’t noticed Cu staring back.

“… excuse me?”

No response, but he didn’t look away. It was almost like Cu didn’t care that he was staring and wouldn’t be assed to stop.

“Do you know why I tolerate you?” Cu asked, suddenly.

“I entertain you, probably.” Diarmuid didn’t give it a second thought. Their sparring sessions had been the only reason Cu would tolerate him, most likely.

“No…” Cu trailed off, but he didn’t seem to know the answer either. He was blunt to a fault, no one ever had to guess what he was thinking. Neither coy or sheepish, the fact that he didn’t have an answer meant that he really didn’t know. “Something else.”

“Something else?” Diarmuid laughed. “I wouldn’t know what.”

Cu looked at him like he was trying to solve an equation to which there was no real answer. Wasn’t there a part of Diarmuid’s legend that he had a mole under his eye that charmed women, or something? That probably wouldn’t realistically work on him… but that brought the correct word to his lips. Charmed. For a man who cared about nothing, to suddenly care about someone was alarming. He wasn’t sure if he wanted to kill Diarmuid or kiss him. His hands suddenly took hold of Diarmuid’s shoulder and pressed him to the shower wall, putting himself directly under the nozzle as he did just that.

(Kiss him, of course.)

Diarmuid was taken aback and nearly knocked his own head back to the tile in an effort to escape it, but Cu’s hand quickly wrapped around the back of his head to hold him in place. He was powerful, so he felt naturally trapped—and all the while, and Diarmuid fought to _breathe_ , he figured Cu Alter was just this way, that he couldn’t communicate for shit and the only thing he knew how to do with his desires was act on them.

Medb would be furious to know Cu Alter was actually giving Diarmuid the time of day and not her. That fact, along with the kiss, gave Diarmuid a bit of pleasure.

It was hard to see with the water spraying directly onto them, so with one hand behind his back, Diarmuid turned the nozzle off.

Cu broke the kiss first, staring at him before wiping his lips on his forearm. What the hell was going through his head? Diarmuid stared up at him in offense. Cu’s lack of communication be damned, he should be warned before taken by the shoulder and _kissed_!

“What the hell?” He demanded, staring up at the berserker with indignance. “You don’t just slam people against the wall and—use your words, damn it!”

Cu looked annoyed at that, though he wasn’t expecting a warm reception either way. “Would you have approved if I asked permission, first?”

“I—” Diarmuid trailed off, before finding his footing again. “I might have, what of it? But you don’t--”

Cu went in for round two, and Diarmuid put a hand over his mouth. “Are you even listening to what I’m saying?!”

“You’re being annoying.” He stated, bluntly. “If you feel the same way, then who cares if we say it first?”

He hadn’t been one to get his wish so quickly. It was as if he’d been passed a grail by his master and asked to wish for whatever was on his mind recently. He could feel the heat off of Cu’s body as they stood stock still with only water droplets rolling down their skin. Cu stared at him with intent, demanding eyes and Diarmuid wished he was less of a romantic. His pride is on the line, yet this may be the only chance he has to get to see more of what lies beneath Cu Alter. He moved his hand back down.

“… does it have to be in here?” He relented. _Finally_ , Cu thought. Attempt at kiss #3 went a lot smoother than anticipated, and Diarmuid practically melted into it. There was no taming the beast, but he was just fine with it this way—his rough kiss, languid and hot, dove deep between his lips and took its time. Cu had no shame in pressing their bodies together, though Diarmuid’s hips twitched away from his in mere instinct. As the kiss broke again, Cu moved for the throat.

Diarmuid sucked in a breath at the sharp graze of his teeth against his neck, expecting nothing gentle as he reached behind himself again and turned the water back on. The startle of the splash had Cu bite into him—which made Diarmuid hiss in pain. He could feel a few of his fangs pierce skin and realized he had a more masochistic streak to him than planned. Shamefully, he was finding himself getting hard as Cu licked the wound.

“Why are you interested in me?” Diarmuid asked, suddenly, as Cu moved down his neck to work more bruises into him. “I thought you weren’t interested _in anyone._ ”

“Don’t know,” Cu copped. “Don’t care.”

There was probably more to it, like how Diarmuid gave him the time of day without being intrusive. How he was always ready to spar with him despite being far weaker. How diligent he was, how he didn’t slack, how he remembered him working beneath him in America—yes, those memories had come back. Diarmuid filled a spot where he was tolerated enough to become liked, and Cu Alter didn’t care to keep attraction in check. There would be no courtship when he could go straight from realizing he wanted him to having him, like skipping straight to dessert.

If he wanted Cu, he would have to accept that this was the way he’d have him. With little words spoken in between, with no romance for the romantic on the other end of it. Diarmuid was touch-starved and each bite reinvigorated him in a way that has him yearning for this to happen somewhere nicer than the showers that anyone could walk in on. He was starting to follow Cu’s lead in not caring, in leaning into him and tangling his fingers in his long hair.

Wordlessly, Cu broke contact and turned the water off.

“Wha—"

“We’re moving somewhere better.”

\--

Thank goodness heroic spirits could move just by shifting from room to room, or that walk of shame to an open bedroom would have been quite a bit worse.

Cu might not have relinquished control if Diarmuid hadn’t insisted upon it, leaving trace kisses down his pecs and waist to move in on his destination. Okay, fine, he was curious about Cu’s length and he wanted to give it a few strokes before moving back up again, but he hadn’t expected so… much. In an eerie thought, he wondered if Medb wished for this in particular? No, well, maybe—what mattered was it felt thick and heavy in his hand and he thought he might break if he took it in, but then Cu shoved his hand atop his head downward, and purely by accident, he leaves a kiss on the head of the shaft.

Diarmuid glared up at him, but Cu only looked down at him expectantly. There was a certain degree of satisfying control in feeling it harden beneath his grasp. Cu lifted a leg to set on the bed while one leg stayed firm on the floor to give him room. Guess he was really doing this.

His tongue poked out of his lips to give it a taste—nothing more than salt and skin, thanks to the recent shower. He grew more and more daring as he stared up into Cu’s red eyes, swirling his tongue around the head before managing to take it into his mouth. He could hear a grunt of appreciation above him and it spurred him on—bobbing his head as he minded his teeth, realizing the importance of how far he needed to stretch his jaw and gaining respect for the girls who had done this for himself before. It was _hard_ , but the results were worth it. Cu was responding in earnest with his hand atop his head, pushing him down a little bit further every time he thought Diarmuid could do it—relinquishing only when he sputtered onto his cock.

His hand stroked along what his mouth couldn’t take, and with a dizzying excitement coupled with his desperate need to breathe, he was eager for Cu to come—but Cu was relaxing and taking his sweet time letting his pleasure build, occasionally lifting his hips into his mouth, gathering his hair at the back of his head to guide them. Diarmuid parted from him with a cough as he busily stroked him off.

“How much longer?”

“You’re not helping by stopping,” Cu responded with his first grin of the evening—sending a shock straight through Diarmuid’s heart. That eager to please part of himself quickly returned to the job, sucking and licking and depriving himself of air to hold his position—it was a wonder he didn’t choke. Grabbing Cu’s hips to steady himself, he tested how far he could take it, feeling it hit the back of his throat and test his gag reflex, and he was only halfway down. Coming up with a heaving gasp, he started to wonder if Cu would ever come or if he was just enjoying the attention like a king on a throne, like he wasn’t worthy of that much.

However, as Diarmuid tucked a stray lock of hair behind his ear, he felt Cu’s muscles tense beneath his touch and his hand tighten its grip on his hair, holding him in place as he came right on his _tongue_ \-- the taste of salt spilling over the corners of his lips as he grimaced around his cock, squeezing his eyes shut as he willed himself to swallow it. He coughed as he pulled himself up and off, nails digging into Cu’s thighs as he tried to regain his breath.

Cu stared at him as if appraising him, then gave another grin. “What stopped you from spitting it out?”

“Didn’t want to make a mess after a shower.”

“Should’ve marked your face then, in retrospect.”

“You would never—”

“I would. And I will eventually, probably.”

This bastard—but Diarmuid was determined to be repaid after his favor as he stood up to straddle Cu’s hips and kiss him harshly, returning that violent side of him with some brashness of his own, but Cu didn’t let him take that lead for very long. Flipping him over onto the bed and pinning him down by the hands on his waist, Cu looked hungry, as if he wasn’t simply satisfied with having Diarmuid suck him off. He wanted more—everything he could be given.

“You’re intending on doing this again--?” Diarmuid hissed as Cu pinned both arms to the bed, the sheer strength making it so that he could only move his legs as Cu greedily wedged himself between them. Cu’s tongue was bestial—again, maybe a preference of Medb’s?—and in each kiss, Diarmuid practically choked with the way it filled his mouth, Cu eager to taste all of himself within it.

“We’ll see.” Because of course Cu would get him addicted to this touch before deciding if it bored him or not—he was investigating Diarmuid’s body for the sake of his own interest, and it was yet to be determined how long it would last.

Cu relinquished his arms and Diarmuid responded eagerly by drawing his nails deep down his back, earning him a pleased grunt from the bigger man, apparently pain and pleasure mixed for him as well. Diarmuid was used to soft touches and trying to mind his partner’s well-being. Cu was all about inflicting any kind of sensation on the other, be it hurt or comfort. It’d been so long since he’d touched someone, and Cu wasn’t exactly the object of his fantasies even if he was the object of his interests— _still_ —

With relative ease, Cu flipped him over. Diarmuid would’ve complained at the rough manhandling were it not for the bite on the back of his neck suddenly taking him by surprise. He really was a _dog_ , wasn’t he? As Cu’s hands moved downward, prodding his ass with intent, Diarmuid called time out.

“You need lubricant, or you’ll make this miserable for both of us—"

There was a dissatisfied look that Diarmuid couldn’t see, but could feel on his back all the same. In a remarkable display of self control, Cu’s hand moved away.

“Where.”

“In the drawer. Da Vinci’s special kind—ah—"

Apparently, they weren’t the only heroic spirits getting their rocks off. Cu opened the drawer, stretching across Diarmuid’s body and found the bottle within, a teardrop shaped glass vial that looked like it could easily break in his hands. “I won’t ask why you have this.”

“Good.”

Drizzling it across his fingers, Cu wasn’t gentle. Diarmuid had to arch his hips to fit the curve of his digits, with Cu smugly commenting that he looked like a dog in heat, raising his body to his touch like that. _Speak for yourself_ , Diarmuid thought bitterly as the motions went from rough to pleasurable, as a second finger probed him and scissored him and stretched him. He was amazed Cu had the patience for this, or even knew what to do in this situation, but when he withdrew his fingers it felt a little too early.

Diarmuid let out a gasp as the heat of Cu’s prick pressed against his ass, apparently reinvigorated in the time it took to toy with him. Maybe heroic spirits just didn’t need recovery time? Because as Cu pressed into him, there was no doubt that he was just as hard as before because Diarmuid felt like he would tear apart. Cu wasted no time for the sake of his own pleasure. He roughly snapped his hips into his, Diarmuid crying out and muffling himself with a pillow. God, he’d … never been taken in this way, so roughly, so—anything like this at all! As Cu began to move, he poured the remaining lube over his cock and flung the bottle to the other side of the bed.

The motions made his head swim. Cu didn’t pause for anything or anyone, and Diarmuid knew in that moment he was lucky and privileged for Cu to take the time to stretch him—this molten heat and pain inside of him was nearly breaking his mind with each thrust. He could hear Cu panting above him, grabbing his hips and riding him out for all he was worth. He really didn’t care if he was hurting Diarmuid or not—he was trying to fuck him out of his mind, so that he wouldn’t have this bizarre fixation on him anymore, like getting it over with would leave him aloof and alone again.

Yet with each fluid motion, he found himself more and more addicted to how tight he was, how he keened with each push. Cu Alter found himself more of a monster than ever when biting down on Diarmuid’s shoulder to hold him in place like a mutt in heat, throwing all notions of kingliness aside for the sake of pleasure. His hips pumped furiously into him and rocked the bed, noisily letting anyone outside the room know that now was probably the worst time to enter. Diarmuid only hoped his voice was indistinguishable amidst the frenzy.

Cu pulled out and flipped him again, this time so he could see his face as he fucked him. Diarmuid was a _mess_ , drool spilling over the corner of his lips and tears welled up in his eyes as he furiously held them back. He reached up to put his arms around Cu’s shoulders only to be pushed back down—so much for holding him.

Cu’s hand wrapped around Diarmuid’s cock and he could hold on no longer—the pleasure building since he had been on his knees in front of him came to a head, spilling semen across his chest as Cu rode him out for his own enjoyment even as Diarmuid fell slack against him. Strength gave him the advantage in holding him up and finishing, panting like a mad wolf as he drew out of him, giving a few last strokes as he came on his waist.

Diarmuid expected nothing else after. No cuddling, no closeness, and true to his expectations, he didn’t get it. Cu only sat up on the side of the bed, untangling himself from his legs and trying to clean himself of the sticky sweat that remained. The door slid open.

“Hey, Master needs to…” Cu-the-Original began, before staring between the two naked forms in front of him, pausing as he decided ‘nope, not today’, and turning and closing the door before Cu Alter could summon his spear and launch it at him.

“Oh, God—” Diarmuid put a hand to his face. “Everyone will know about it.”

“Let them.” Cu clearly didn’t care about who knew, and maybe even took a little pride in it. No one would touch Diarmuid now, and he wanted it that way.

Get fucked, Fionn. Diarmuid served a new man now.


End file.
